Gearing



- (N0 Model.)

B. CAMPBELL.

GEARVING.

Patented Feb. 5, 1884.

n. PETERS. PbotoLilhogmpher, Wmhingwn. m c.

' To all whom it may concern:

I llnirnn STATESv PATENT Q F CE.

.ROBERT CAMPBELL, OF ALLEGHENY, PENNSYLVANIA.

GEAR'ING.

SPECIFICATION forming Be it known that 1, ROBERT CAMPBELL, a citizen of the United States, residing in Allegheny, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Gearing, of which the following is a specification.

My invention relates to gearing in which a double lever is engaged by a grooved or slotted driving head or wheel.

The objects of myinvention are the avoidance of a certain amount of friction and provisions for an increase of power or speed in machinery.

The mechanism by which these objects are attained is illustrated in the accompanying drawings, which form a part of this specification.

Similar letters refer to similar parts throughout the views. Figure 1 represents a driving-head forming part of a piston-rodor connecting-rod, and.

' grooved or slotted to engage a double lever in connection with a pitman or connecting-rod. Fig. 2 is a driving-head engaging two levers connected with rods attached to cranks. Figs.

3 and 4. are top views of the same, Fig. atshowing it in frame. Fig. 5 is a groove-wheel en- .gaging two levers, and Figs. 6 and 7 are end and top views of the same. Figs. 8 and9 are grooves formed on arcs of one hundred and twenty degrees and ninety degrees, respectively. Fig. 10 is a circle on which the arcs shown in Figs. 8 and 9 are formed. Fig. 11 is a joint ed connecting-rod.

As the principles guiding to the adoption and application of these mechanical forms and connections are not obvious nor capable of illustration by model, the steam-engine is referred to and used in illustrating the character and efiects of the invention. To this endlet us conceive the pitman or connecting-rod of a steam-engine to be separated from the crosshead, and a grooved or slotted driving-head to be substituted for the cross-head, as in Figs. 1 and 2. The groove or slot is constructed, as in Figs. 8 and 9, so that the curves on the opposite sides of the grooves present their terminations or projecting ends toward the bottoms of the opposite curves, the apexes on a common line or on two opposite parallel lines. The action required of the curves being simply hypocycloidal, the points of the projecpart of Letters Patent Nd. 292,791, dated February 5, 188 1,

Application filed April 12, 1883. (No model.)

tions may be square-faced, round, or pointed, as they do not act as bearings.

In Figs. 2, 3, 6, and 7, the levers B are fulcrumed on E and operated by the engagement of the arms'furnished with the anti-friction rollers P, which receive the action of the curves D, Figs. 1 and 2, &c., when the driving-head A is actuated by the piston or pitman connected with it, or, if in the cam-wheel M, rotary motion is produced by any engaged motor.

The value of the hypocycloidal curve, as here combined with a double lever having a central fulcrum and an action intended by the formation, position, and engagement, as herein shown and described, is not suggested by an inspection of themechanism or its action, but from an examination of the conditions of the assembled parts and the possible results of their combined action when various forms and proportions are used.

It is a fundamental design to avoid using the crank-circle in the common manner, and to piston, and this renders it possible to duplicate the number of revolutions of the crank attached by a single piston-stroke; or, in onev case,to enlarge the piston-surface two or three fold or, in another case, to save one-half or twothirds of the steam, and still obtain the present speed, power, effects, or results; indeed to gain two hundred or three hundred per cent. in power or speed. For example:

Crank circle. Lever No. Lever No. Are 180 180 Pitch 50 45 2215 Piston-stroke 24 in. 12 in. .8 in. Crank 12 in. 12 in. 5 in. Full leverage.... 12 in. 15 in. 9 in.

The circle and arcs are on acommon radius.

InFigs. 6 and 7 four connecting-rods are shown, but only two are needed, practically, as they are engaged at right angles'on the shaft, being engaged in the groove at different angles, one being at full throw and the other at half throw, as shown in the drawings.

I am not aware that a groove-wheel or driving-head having curves and engaging a double lever, in'eombina-tion with a piston-rod or conneeting-rod, as herein described and shown,

5 has ever been used or claimed in the form and for thepurposes set forth. Therefore I elain1 1. In gearing, a double lever, f ulcru med, eonneoted, combined, and engaged in the form, 10 manner, and for the purpose set forth.

2. In gearing, grooves or slots engaging a double lever, in combination with it connecting-rod or piston-rod when the grooves or slots and lever are engaged and of construction and I 5 bearing as described and set forth.

ROBERT CAMPBELL.

Witnesses:

J. L. ALSTOX, S. A. Hays. 

